#define _CRT_SECURE_NO_WARNINGS
#pragma comment(linker, "/stack:16777216")
#include <string>
#include <vector>
#include <map>
#include <list>
#include <iterator>
#include <set>
#include <queue>
#include <iostream>
#include <sstream>
#include <stack>
#include <deque>
#include <cmath>  
#include <memory.h>
#include <cstdlib>
#include <cstdio>
#include <cctype>
#include <algorithm>
#include <utility>
#include <time.h>
#include <bitset>
#include <random>
using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define RFOR(i, b, a) for(int i = (b) - 1; i >= (a); --i)
#define ITER(it, a) for (__typeof(a.begin()) it = a.begin(); it != a.end(); it++)
#define FILL(A,value) memset(A,value,sizeof(A))

#define ALL(V) V.begin(), V.end()
#define SZ(V) (int)V.size()
#define PB push_back
#define MP make_pair
const double PI=acos(-1.0);

typedef long long Int;
typedef long long LL;
typedef unsigned long long UINT;
typedef vector <int> VI;
typedef pair <int, int> PII;
typedef pair <double, double> PDD;

const int INF = 1000 * 1000 * 1000 + 7;
const LL LINF = INF * (LL) INF;

const int MAX = 100007;
const int MAXK = 51;
const int MAX2 = 24000000;
const int LEN = 21;
const int BASE = 1000000000;

char S[MAX];
char T[MAX];
int A[MAX];
int B[MAX];
int P[MAX][36];

int get(char x)
{
  if (x >= '0' && x <= '9') return x-'0';
  return 10 + (x-'a');
}

int main()
{
  int t;
  cin >> t;

  FOR (tt,0,t)
  {
    scanf("%s", S);
    scanf("%s", T);

    int n = strlen(S);
    int m = strlen(T);

    FOR (i,0,n) A[i] = get(S[i]);
    FOR (i,0,m) B[i] = get(T[i]);

    int res = INF, pres;

    FOR (i,0,36) P[n][i] = n;
    RFOR (i,n,0)
    {
      FOR (j,0,36) P[i][j] = P[i+1][j];
      P[i][A[i]] = i;
    }

    FOR (i,0,n)
    {
      int p = i;
      FOR (j,0,m)
      {
        p = P[p][B[j]]+1;
        if (p > n) break;
        if (j == m-1)
        {
          if (p-i < res)
          {
            res = p-i;
            pres = i;
          }
        }
      }
    }

    FOR (i,0,res)
      printf("%c", S[i+pres]);
    printf("\n");
  }

  return 0;
}